Cracked Cases

[CP]

Anyone have an idea what’s going on here?  Overpressure is the obvious answer but I’m below the Max recommended load.  Could it be something else?

[Bookworm]

Are there any signs of pressure on the bases. Just because the book says you are under max pressure doesn't mean you aren't.

[Ray]

Looks like old brass. Sometimes I get neck splits when using older brass. That's when I usually retire that batch/lot no. This almost looks like a variant of that. You may want to look for more stout brass too and consider reloading it less times.

Read this. http://www.firearmstalk.com/forums/showthread.php?t=2660

[demontang]

If that brass as been reloaded a few times it could just be the brass. My reloading book talks about the cases doing that after being reload to many times.

[300rum]

Are you using a full size die or are you neck sizing?  If you are full resizing you are probably overworking the brass.  I always had to use a full die when resizing belted mags and by doing this I only loaded them a couple of times because it works the brass quite a bit.

[Slenk]

Looks like they been loaded one to many times. Don't rely on books for max loads you need to work up loads for each gun. If you take a piece of wire and sharpen one end and then bend it in a L shape, you can check your brass inside for a indentation where yours are cracking . If you feel any indentation throw the brass out.
Slenk

[CP]

Thanks for the all replies, they are very informative. 

This lot of reloads is the 3rd firing (two reloadings) of mixed brass (Win, Rem & Fed).  All brass was full sized once and neck sized once.  There is some flatting of the primers but it is not excessive.  I checked all the cases with a wire as suggested and found a couple with internal cracks that haven’t gone all the way through yet. 

All the cracked cases are Winchester; there are no cracks in any of the Federal or Remington brass.  So it looks like I have a combination of over-pressure and weak brass.  I’m tossing all of this lot of brass and I’m going to retire this loading.  Which is a shame because I really like this load. 

[jeff100]

The brass in cartridge cases flows forwarded a bit with each cycle of shooting/reloading.  That's why cartridges become longer and eventually need trimmed.  That flowing forward causes the brass walls to thin near the base of the cartridge.  If pressure really isn't an issue, then this could be the cause of your failures.  Try new brass if you really like the load, and use a good quality brass.  If you're still suffering this type of failure with new brass, you might want to rethink your pressure analysis.

Hmmm.  Unless...could this be a headspace issue?  Belted magnums headspace the cartridge on the belt IIRC, not sure if that could be an issue here or not....might want to consult a competent gunsmith.

[Coasthunterjay]

it doesnt look like old brass.....

what dies are you using to reload?

what grain powder and type of powder are you using?

what caliber?

I think this is a head space issue maybe o maybe aseating problem with your dies.....but?

[Big10gauge]

Head seperation can be caused by excessive headspace, overworking your brass when resizing it, or the brass has just been reloaded too many times. It is one of the most common forms of brass failure and one of the first things you need to look for when reloading. Loading hot loads quickens the process. You might want to try neck sizing or backing your full sizing die out a little bit so it doesn't bump the shoulder back so far. I'd get your gun checked with some no-go go gauges for a starting point.

[MHWASH]

Big10 took the words out of my mouth.

[Ray]

It certainly could be a headspace issue. I would not rule it out. I lean towards overworked brass which creates thinned brass walls = old brass which needs retiring. If you buy or use a brand new lot of brass and the issue does not happen again it could be concluded. Maybe even a different load too. A high pressure load will wear our your brass faster than  lower pressured ones.

[jeff100]

When I looked at this post early this AM (after being up all night) I thought that brass was belted cases.  Now looking again, I don't see any belt, just deformation.  So I'd say this is either weak/worn out brass and/or still possibly a head space issue.  I'd have a gunsmith check the head space to be sure that's not an issue, and as I said before, try new quality brass...

[12Gauge]

It appears more like a combination of a oversize chamber and brass being loaded to many times.  Take it to a gun smith to be absolutely sure.  Using a neck sizer and only loading your brass a couple of times my cure the problem.

Look a the primer, is the primer seem to be coming out or protruding out? if so them it is more likely to be a head spacing issue.

[Slenk]

CP
If you are seating your bullets out to far and they are touching the rifling lands you will create alot more pressure. I have several rifles that I can not seat the bullets to book specs. And have to seat shorter.
Slenk

[wrangler]

it's called case head seperation. each time you size a case the brass is streched. if a case has been reloaded too many times that's what you end up with. if you have a fairly tight chamber there really is no need to full length size every time. a neck sizer won't put the unneeded stress on the brass. it's not related to pressure. time for some new brass!

[dbllunger]

Skipped all the way to the front.  Problem is real simple....TOO MUCH HEAD SPACE....!!!! Not a major problem if your rifle is accurate.  I have a 300wm that drives tacks but eats brass.  Not uncommon on belted mags because they seat on the base instead of the neck.  If if drives tacks live with it and count reloads, but if not have it set back to minimum and it will shoot a couple more times.  Better yet go to to a mag based on the 404 and the brass will last as long as the old 06.  Not a crisis as it never does it the first round,  and if it it does then you have major problems and a 1-2 threads will be needed.  Personally screw the belteds with the new mags factory loaded with factory brass.!!!!!!!!!!!!!!!!!!!!!  Load them to the top and and then some and they like it...just like the old college co-ed.   Man those were the days.

[CP]

Thanks for all the replies.  The rifle in question is a sporterized Remington made model 1903A3 30-06, manufactured in Jan 1944.

Headspace checks good.  Maybe it’s just weak brass but since she’s going on 65 years now I’m going to back off the load. 

[jeff100]

Is your load hotter than max load in the manuals for the powder you're using?

Have you chronographed the load?

Can you provide a photo of the end of the case, so we can get a good look at the primer (for primer analysis)?

[CP]

Is your load hotter than max load in the manuals for the powder you're using?

No

Have you chronographed the load?
No


Can you provide a photo of the end of the case, so we can get a good look at the primer (for primer analysis)?

I'll try, but I’m not too good at photography

[CP]

These look nasty when enlarged like this:

[deaddog]

Skipped all the way to the front.  Problem is real simple....TOO MUCH HEAD SPACE....!!!! Not a major problem if your rifle is accurate.  I have a 300wm that drives tacks but eats brass.  Not uncommon on belted mags because they seat on the base instead of the neck.  If if drives tacks live with it and count reloads, but if not have it set back to minimum and it will shoot a couple more times.  Better yet go to to a mag based on the 404 and the brass will last as long as the old 06.  Not a crisis as it never does it the first round,  and if it it does then you have major problems and a 1-2 threads will be needed.  Personally screw the belteds with the new mags factory loaded with factory brass.!!!!!!!!!!!!!!!!!!!!!  Load them to the top and and then some and they like it...just like the old college co-ed.   Man those were the days.

+ 1 I think you got it right.

[jeff100]

Primer pic is fine, and looking at these primers I would agree with you, I see no signs of excess pressure in the primer analysis.  I use a chronograph for all my testing these days, but I spent a couple of decades without one, and got pretty fond of primer analysis for evaluating rifle loads.  Even with the chrono, I still do constant primer analysis as an extra data point and reality check.  Old habits die hard I guess. 

I'm agree with everyone else who has suggested case head separation is most likely from too much head space...thanks for posting the picture...

Jeff